Super CDs will contain whole feature films

A SMALL British company has squeezed enough information on to the surface of an ordinary 12- centimetre compact disc to play an entire feature film with stereo soundtrack.

The new 'double density' CD, which will cost no more than ordinary compact discs, will even play on selected models of existing players. It needs only a simple pounds 100 adaptor to let existing televisions play back the two and a quarter hour colour video CDs. Nimbus, based in Monmouth, Wales, has shocked its Japanese competitors with the system.

The surface of a CD carries a continuous spiral of pits and spaces. A laser scans this digital code to play back the sound or video image it represents.

Until now, it had been thought that CDs could hold no more than an hour of video information and the only way to store more information on the surface was to use blue lasers, with a short wavelength, which could focus on smaller pits and spaces. Such lasers are a few years away from commercial production.

By 'happy accident', however, Jonathan Halliday at Nimbus found that the lasers in today's CD players focus more sharply than is absolutely necessary, and can distinguish the closely packed pits on his new double density discs. It should not be hard, therefore, for manufacturers to 'tweak' the optics in players to guarantee the discs play perfectly every time.

Nimbus expects to have a prototype recordable version of its video CD ready within a year. This would pose a substantial threat to video tapes, since people would one day be able to record their own video CDs. These would be as convenient as music CDs, with the player moving straight to the start of a film, avoiding the need to wind the video tape backwards and forwards to find the right spot.

Nimbus was formed in 1971 by Count Alexander Numa Labinsky, a Franco-Russian singer (better known to opera fans as Shura Gherman) who was disillusioned with the quality of the music recordings. In 1984, Nimbus became the first UK CD manufacturer.

In another technological advance, the trip to the video shop may become a thing of the past.

According to British Telecom, video and computer games shops could soon send their wares by telephone, straight into the living room.

Andrew Kenyon, head of the BT team that sells the digital network this requires, said: 'We are right on the doorstep now of a time when people will send usable video images down the telephone line.'

He believes it will be commonplace within a few years to ring the local video shop and ask it to send over samples of the latest computer game, or snippets from films on a shortlist. The shop would stock a 'master' of each film. Once the customer had made a selection, the shop would send it down the line on to a recordable video compact disc, linked to a television. No new cabling would be needed because the latest digital services will work on the same copper telephone wires used at present for speech.

The system works by compressing the video signal and sending it out over BT's digital telephone service (known as the Integrated Services Digital Network, or ISDN). Leasing the system will cost a few hundred pounds a month, plus the cost of an ISDN line (about pounds 80 a quarter after the pounds 400 installation charge).